The following data was taken from the nameplate of a commercially available hybrid vehicle battery and from testing the battery. The battery power rating was 21 kW, 201.6V, 6.5 Amp-hrs. The nominal current was 21000 w/201.6V=104 A. The battery was rated at 104 A for 6.5 Amp-hrs./104 Amps=224 secs. However, testing showed that producing the maximum specified motor torque of 400 Nm would require 350 dc amperes of current. The fully charged battery under this condition can only lasted for 6.5 Amp-hr/350 A=66 secs.
The battery consideration is particularly important for the plug-in electric and hybrid vehicles for reducing the current requirement during starting and for accelerating in traffic. It is therefore an object of the invention to improve starting torque while reducing starting current requirements.